Electrically-propelled aircraft



ELECTRI CALLY PROPELLED AIRCRAFT "/'ATToRNEY Oct. 14 .y 1924.

A. L. DRUM ELECTRICALLY PROPELLED AIRCRAFT Filed Feb. 18 1921 Jah/6 4 Sheets-Sheet 2 INVENTOR BY' Q ATTORNEY Oct. 14 1924. 1,511,448

. A. l.. DRUM ELECTRICALLY PROPEIJLEDV AIRCRAFT Filed Feb. 18. 1921 4 sheets-sheet- 3 INVENTOR ATTORNEY A.L.DRUM

ELECTRICALLY PROPELLED AIRCRAFT Oct. 14, 1924. 1,511,448

Filed Feb. 18. 1921 4 SheetsSheet 4 INVENTOR ATTORNEY .Patente-cl Oct. 14, 1924.

PATENT oFFlcE.

ALPHONSUS I. DRUM, 0F CHICAGO, ILLINOIS.

'A fnLmraIcaLLY-PROPELLED nnenar'r.

.Application led February 18, 1921. Serial No. 445,918.

l To all whom 'it may concern.'

Be it known that I, ALPHoNsUs L. DRUM, a citizen of the ,United States, residing at- C-hicago, in the county of Cook and State of Illinois, have invented certain new and useful Improve-ments in Electrically-Propelled Aircraft, of Awhich the following is` a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention krelates to.` air-craft and more particularly to air-craft .wherein the-l propellers are driven by electric motors.

It is an object `of the invention to provide an improved` system of air-craft 'propulsion wherein` great flexibility and delicacy of control is secured resulting in ad` vantages in maneuvering the'air-cra'ft and in regulating the speed thereof.

It is aLfurther object to provide-an iniproved system of aircraft propulsion readily lending itself to accuracy in balancing the air-craft resultin in increased stabil.- ity and fconsequent re iability in -flight, and in the execution -of variousmaneuvers.e

-It` is aLfurther object to provide means for air-craft propulsion including a novel and flexible s stem 'of power distribution and control ,w ereby the propelling means? mayv be advantageously disposed .at various portions in the air-craft for securing stability, and flexibility rin executing maneuversf Another object is to provide an improved system-of air-craft pro ulsion wherein electric energy is generate at a central power plant under the control of .the pilot anddistributed for driving the propelling means. t a

Otherobjects will be in part obvious as the detail description roceeds and in part pointed `out in connect-ion therewith.

The` invention accordingly consists in the features of construction, combinations of elements and arrangement of parts which will be exempliied in the construction hereinafter set forth, and the scope of the application of which will be indicated 'in the following claims.

In the' accompanying drawings wherein an illustrative embodiment of the invention is disclosed,

Fig. lis a sideelevation of an airplane) Fig. 2l is a front. elevation thereof;

Fig. 3 is a fragmentaryenlarged view 1 of a detail showing the driving mechanism for one'of thelifting propellers and means for shifting the same from lifting position to flight position; 1 f

Fig. 4 is. a front elevation of Fig-3, the propeller being removed;

Fi 5 isa diagrammatic `view showing the e ectrical connections for controlling the driving motors;

Fig. 6 is a' side elevation of a modification' embodying .the invention; a

Fig. 7 is a front elevation thereof; and Fig. 8 is an enlarged fragmentary view showing the arrangement for one of the liftin propellers.

Re erring first to thehembodiment` shown in Figs. 1.-to 5, for the"'pur ose of illustrating the application of t is invention an air-plane of the biplaneA type is shown having a fuselage or nacelle 1, upper and lower planesl 2 and 3, a landing chassis 4,

vertical rudder 5 and elevator flaps 6. The .fuselage is 'provided'adjacent the planesadapted-to be driven by gasoline or oil. Itv

is to be understood, however, that some other type of prime mover, such as a steamor gas turbine or reciprocating steam engine',is contem lated and may bel substi;ll`

tuted for the internal combustion motor shown in the drawing. In case steam is tol be employed as motive power, steam generating apparatus of suitable design, preferably employing oil or other fuel, will be provided and suitabl mounted in the forward portion of the uselage.

.An electric generator 10 is connected to be driven by the prime mover 9, the 'shaft 1l of the latter being preferably extended to include the shaft of the generator motor, forming a .direct-connection between the driving and drive-n elements. This generator mav'be of the alternating current ty which is preferred for simplicity of regu ation of the system and freedom from sparking, or it may be vof the direct-current type having a commutator 12 and commutator brushes' with conductors leading therefrom to supply energy for driving the propellers as will be disclosed more in.' detail hereinafter.

One' or more drivingpropellers are provided for driving 'the air-craft in flightl through the air, this being shown in the illustrated embodiment as a single tractor propeller 13 suitably rotatably mounted in the forward portion of the fuselage in rigid position, an electric motor 14 heilig directly connected to the propeller-shaft and suitably mounted in the framev in the fuselage. In order to raise the airplane from the ground substantially perpendicularly preparatory to flight and Without any preliminary run along the surface of the earth, ont` or more vlifting propellers may be provided as shown in Figs. 1 and 2. Such lifting pro- ,pellers 15 and 16 are employed mounted at the leading edge of the Aupper plane and spaced on 'each side of the vertical plane ol' the fuselage. As shown particularly in Figs. 3 and 4 each of these lifting propellers has a drivingmotor 17 or 18 direct-connected to the respective propeller shaft, each motor being pivotally carried upon trunnions 19 mounted in a bracket 2O secured to the upper plane, a stop or lug 19 limiting turning movement in one direction on the trunnion. This pivotal mounting provides. means whereby the propeller and its drivin motor are movable as a unit in a vertical 1v ane enabling the propeller to exert a liftingzeii'ort upon the airplane or to assist in the flight ofthe same through the air. Manually operable means under the control of the pilot are provided for simultaneously shifting the lifting propeller from lifting position to driving position and vice versa, but it is obvious that an electric motor under the control of the pilot may be employed for this purpose. As shown, this means comprises segmental gears 21 rigidly secured to the trunnions 19 of the motors, the teeth thereof engaging worms 22 adapted to be driven by iexible cables 23 wound on drums 24, the latter being rigidly secured to the pilot. By this arrangement it is obvious that the lifting propeller y be moved as desired by appropriate rotation of the drum 26, the propellers being thereby positioned to exert lifting effort or driving effort upon the airplane.

The respective propeller mot-ors are electrically connected to receive energy from lthe generator 10 of the central power plant,

These iiexible cables and controlvmeans are provided for individual or collective control thereof. Means for controlling the speed of the prime mover andthe vol-tage of the generator are also provided, the various controlling devices being located in the c'ock-pit conveniently ac cessible to the pilot.` Any approved construction for this control may be employed, a diagrammatic view of a system embodying one form being shown in Fig. 5, and 4an arrangement of the manual elements for controlling the same being show-n' in Fig. 1. As shown the prime mover or motor 9 is arranged to be supplied with fuel from a reservoir 27 bya conduit 28, a valve 29 in the latter being connected for manual control by a rod 30 and lever 31 whereby the speed of the prime mover may be regulated as desired. Main conductors 32 and 33 lead from "the generator brushes to conduct energy to the'respeotive propeller motors, the gen- '.erator shunt field being connected across the main conductors through an adjustable controlling rhcostat 34 'by conductors 35,l and 36 whereby the generator voltage is under the control of the pilot. The main conductor 33 is connected' to one terminal of a controller 37 of any approved design, and a conductor 38 is connected to the other ter-- ininal thereof, conductor 38 being connected to one end of each of the resistance coils of adjustable rheostats 39, 40 and 41. The

"conductorg38 isY also connected to the adthe engine Speed through the control valve llo 29, by adjustment of the generator voltage throughthe field rheostat 34, or by operation of the controller 37. It ,will be-'noted that adjustment of the controller 37 controls simultaneously the 'energy delivered to all the driving motors. Individual control of each motor is securedrby .individual ad' justment of the rbeostat 39, 40 or 41 connected in the -individual circuit of each motor. By this arrangement it will be seen that' a particularly fiexible control system for the propellers is secured with consequent flexibility and delicacy of control of the movements of the airplane in Hight and in the execution of various maneuvers.

The. operation of this system of propulsion' is embodied in the foregoing description und the saine will be clear te those skilled in the art without relteratlon.

lIn large types of airplanes two or monA underthe control of the motors direct-connected to each, these propellers. being disposed on the airplane to secure most advantageous driving conditions and balance.

In a modification of the invention shown in Figs. 6, 7 and 8 the s stem of propulsion as articularly describ above is ap lied to a irigible balloon of ithev lighter-{giaIi-airy type. As shown' 'a nacelle 50 is suspended from the gas bag 51 in the usual mannerthe driving propeller 52 being direct-connected to an electric motor 53 energy being supplied to the latter from a generator 54 'dif rect-connected to a prime mover, 55'. lLifting propellers 56 and 57 are supported on brackets 58-extending from opposite sides of the nacelle and are driven by electric motors 59 and 60 direct-connected thereto. Each motor is preferably mounted on its bracket 58 by trunnions 61 and is adapted to be` swung with its the posjitlon shown in Fig. .7 or driving effort as shown in Fig. 6.' These propellers may alsobe swung to exert downward effort to cause the dirigible'to move downwardly. Turning movement of is effected. by means o a toothedgear 62 secured on 'tr'unnion 6l, a pinion- 63 mounted on a driving shaft64 enga ing the gear 62. The system of control for t e propelling system of this embodiment is similar to that shown in Fig. 5 and described in detail' above. By the system of propulsion as disclosed it is evident thata iexible system of control is provided for directing the diriible in flight and in the various maneuvers ltmay be called' upon to execute."

In the system of electric propulsion and control above described asap lied either to an .airplane or to air-craft of the lighterthan-air type it is obvious that the speed of any prope er motor' may be individually lcontrolled' or theAJ speed of several motors may be simultaneously controlled Also the controllers may be arranged so as to stop or reverse the'direction of' rotation of lany individual pro eller motor or to simultaneously reverse al or a plurality of said motors, whereby it is possible to check *the speed of the air-craft suddenly' or even to drive the same` rearwardly in cases lof emergency. Sharp turns `to right or left, upwardl or downwardly, may also Abe accomplishe by reversing appropriate propeller motors. As

a single example, assuming that the system of control herein described is a plied Ito that type of airplane provided wit two tractor Also in l propeller to`exert lifting effort inl propellers 56 and 57vl propellers spaced on oppositeA sides of the uselage,a sharp turn to the right may be executed by slowing down, stopping or rteversing the motor'of the right tractor propeller while the left is 'operatingat full speed to drive the aircraft in forward direction.' Itis also obvious that a similar maneuver toward the left may be executed byucoitrolling the operation of the left prope e many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in-the above description or shown in the accompanying drawings shall be interpreted as illustrative and not'in a limiting sense.

Itis also to be understood that the lanlguage used in the following claims is intended to cover all ofthe genericr and specific features of the invention herein described, and all statements of the scope of the invention, which, as a matter of language, might be said toy fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent'is:

l. In a system of aircraft propulsion, in combination, spaced flight 'propellers for the aircraft, an electric driving motor connected to each of said propellers, a 4 central power;

plant including aprime mover and an electri'c generator connected tol-be driven thereby for suppl ing energy to all of said motors to furnish t e principal flight propelling force and auxiliary controlling force to the propellers, a* plurality of independent controlling means under control of-a single operator for controlling the power` plant to regu'- late'collectively the energy delivered therefrom to' all of vsaid propellers, and control- 'ling means under the control of the operator for jcontrolling, independently of the first mentioned'controlling means, the individual delivery of energy to each of said propellers.

2. In a system 'of aircraft propulsion', in combination, a main flight propeller and auxiliary controlling propellers for the aircraft, an electric driving motor direct connected to each of said propellers, l,a central power plant including a prime mover andan electric generator connected to be vdriven thereby for supplying energy to all of said motors to furnish the principal flight propellingforce and the -auxiliary control force to the pro llers, 'controlling means under control of t e pilot for direct control of the power plant t-o regulate collectively the energly' delivered therefrom to all of said propel ers, means to control collectively all of said propellers independently of direct power plant control, and controlling means independently of said first mentioned controlling means, the individual delivery of energy to each of said ropellers.

3. ln a system of aircraft propulsion, in combination, a propeller for the aircraft, an electric motor connected to said propeller, a power plant including a prime mover and an electric generator connected to be driven thereby for supplying energy to said motor7 n plurality of independent controlling means under control of a single operator for controlling said power plant to regulate the energy delivered therefrom to said propeller, and controlling means undervcontrol of the operator for controlling independently of said first mentioned controllin means the energy delivered to said prope ler.

4. ln combination, an aircraft of the heavier than air type having a fuselage and a laterally extending stationary sustaining plane, a flight tractor propeller disposed adjacent to and forwardly of saidplane, an additional propeller for the aircraft spaced from said first propeller, an electric driving motor direct connected to each of said propellers, a central power plant carried in said fuselage and including a prime mover and an electric generator connected to be driven thereby for supplying energy to said motors t-o furnish the principal fiight propelling force and auxiliary controlling force to the Propellers, controlling means under the control of the pilot for direct control of the power plant to regulate collectively the energy delivered therefrom to said propellers, means to control collectively the energy delivered to said propellers independent of direct power plant control and controlling means under control of the pilot for controlling independently of said first mentioned controlling means the individual de livery of energy to each of said propellers.

5. ln combination, an aircraft of the heavier than air 4type having a fuselage and a laterally extending stationary sustaining plane, a main flight tractor propeller disposed adjacent to and forwardly of said plane, an electric motor connected to drive said propeller, a central power plant carried in said fuselage including a prime mover and an electric generator connected to A be driven thereby for supplying energy to said motor to furnish the principal flight propelling force to the propeller, a plurality of independent controlling means under control of a single operator for direct control of the power plant to regulate the energy delivered therefrom to said propeller, and controlling means under control of the operator for controlling independently of said first mentioned controlling means the energy delivered to said propeller.

In testimony whereof I affix my signature in the presence of two witnesses.

ALPHONSUS L. DRUM. Witnesses E. A. TURPIN, E. L. PALMER. 

